Glad you found it interesting. The actual 'interpretation' of the display was even more complex as the more experienced operator would have been able to identify many other aircraft configurations we haven't been able to cover here.
Excellent documentary. I read RV Jones "Most secret War" and "Radar, the invention that changed the world". What a great piece of history, thanks for posting.
Great stuff! The display is much like a "PAN Scope" except upside down, and used for difference in distance, not difference in frequency. Thanks for sharing this!
Glad you liked it. Indeed, there were several other types of similar 'A'' screen displays in use at about the same time, featuring both upwards and downwards pointing pulses, with some even using a combination of both!
This is a very good video. After I watched it I noticed that you made a comment. I love Mr. Carlson's Lab. I've learned a ton from your excellent videos....thanks Mr. Carlson
@@michaelshore2300 Hi Michael, is radar not used to judge distance? Yes it does this through reflection time, much like time domain reflectometry, but the end result is distance, is it not?
Philco made IFF units at 3130 West Monroe Street in Sandusky, Ohio. Today, that's the Okamoto Sandusky Manufacturing, Llc building. If you look closely, you can see the old "Philco" sign over the door in Art Deco Stainless steel. 73 DE W8LV BILL
Interesting. Sounds much like here in the UK, where most electronic products used to be made in this country using UK sourced components. I doubt if anything remains of the industry today :-(
Chain Home used 27MHz and an improved version, Chain Home Low, used 40MHz which allowed greater resolution and so could see low flying targets. The transmitters just illuminated a broad area.
@@lishaton The reason for the choice of 27 MHz is more interesting. While most scientist agreed the higher frequency the better Watson Watt was more practical and de asked "what gave the best reflection ?" A dipole "what was the wing span of a German bomber?" average about 80 feet so that set the frequency and UK industry had equipment available at about that frequency. The goniometer was used on the receive signal and gave Bearing but very poor height information . Radar Technician Locking 1953
@oml81mm Rubbish!!! Chain Home Low was a beam radar with a turntable aerials. It was based on the early ASV/AI radar frequency of 200 MHz and development was originally done as a coastal defence (CD) gun laying radar for the Army. Development started for the Army CD set in 1938 and the redesign to convert them to CHL for the RAF started in July 1939. Switched lobe receive aerials were built into the design from the start so an operator could compare two opposite peaks on the CRT and turn the aerials until they got two equal peaks that gave accurate bearings. Range resolution wasn't so hot and there was no height finding. Maximum range was 25 miles and minimum height was 500 feet over the sea. The first CHL radars were pretty much all lash up experimental equipment's using whatever suitable transmitter and receiver systems were available, so no two stations were alike. First Operational CHL station ready by April 1940, 25 in service by the start of the Battle of Britain, however a number of them were based initially on modified Army Gun-Layer (GL) Mk 1 sets which worked at 54.5 to 85.7 MHz. By the start of 1941 plans were in place to upgrade all of the CHL equipment to a common standard with 60 mile range high power transmitter, Single Antenna with T/R Switch for common Transmit / Receive, Motorised Antenna Rotation (instead of hand crank) and a PPI display. 5 such systems were operational by the end of 1941, the first being operational in August 1941). 40MHz kit was the Mobile RDF Unit (MRU), a truck mounted transportable CH system for overseas use by the Army and Battle Damage cover radar for the CH system.
When Wimperis sought an expert in radio to help judge the death-ray concept, he was naturally directed to Watt. He wrote to Watt "on the practicability of proposals of the type colloquially called 'death ray'" The missing technique that made radar practical was the use of pulses to determine range by measuring the time between the transmission of the signal and reception of the reflected signal. This would allow a single station to measure angle and range simultaneously. In 1924, two researchers at the Naval Research Laboratory in the United States, Merle Tuve and Gregory Briet, decided to recreate Appleton's experiment using timed pulsed signals instead of the changing wavelengths.[17] The application of this technique to a detection system was not lost on those working in the field, and such a system was prototyped by W. A. S. Butement and P. E. Pollard of the British Signals Experimental Establishment (SEE) in 1931. The British Army War Office proved uninterested in the concept and the development remained little known outside SEE. wiki
Thank you for producing this great video. I have worked as a network engineer monitoring comms systems with alerts that needed to be analysed and responded within minutes of alarms been recorded. The stress levels could be vey high sometimes, when unexpected events occurred. It must have been a boring and tedious job to watch a radar screen for hours and not good for the eyes but their diligence was essential to the safety of x1000s of other people. Do you know of any accounts of radar history written from the perspective of the operators? In my view they don't get enough credit for the work they performed.
Thanks for the positive comments! I agree. It certainly sounded like a very unrewarding but essential job to me. I do not have any account from any of the chain-home operators myself, but am sure there must be. Maybe the Imperial War Museum might have some in their archives??
In the context of this development , it had little to do with the military might of the US. Uk was miles ahead of the Yanks. My guess is who ever wrote that, is a historicaly ignorant yank.
Out of all the reasons we are not doing the Goose Step - we owe the greatest debt to Communist Russia. They'd already pretty much defeated the Nazi's before Merica had a real impact. Oh - and the wonderful people at Bletchly Park
Have I got this right? To find the position of an incoming enemy formation you needed at least two neighbouring transmitter/receiver stations: A and B, say. Although you were not able to measure the bearing of the formation from station A, you could measure its range. The same was true for B. Draw an arc, centred on station A, with with a radius equal to the range from A. Draw a similar arc centred on B. The point where the two arcs intersect is the position of the enemy formation.
Essentially yes. As you've just said, using the info. from just one, then whilst you know how far it is from that particular transmitter station, but wouldn't know it's bearing. With later radar devices such as the ASV radar, although just one transmitter is still used, by having a receiving aerial on both wings of the aircraft, it was then possible to home in on it.
The Chain Home receiver has a pair of orthogonal dipoles, supported by four masts, a goniometer is used to find approximate bearing from these inputs . Triangulation from a pair of stations could give a better fix but was not essential.
@@paulpotter1041 Yes, I had noticed that the receiving masts were arranged in the form of a square whereas the four transmission masts were in a straight line. It made me wonder if this was a precursor of the high-frequency direction-finding (HF/DF or "Huff Duff") aerial system used by convoy escort ships to locate the bearing of short transmissions by U-boats in the Atlantic.
I have always wanted to see how the radar was actually read. Thank you so much :-)
Glad you found it interesting. The actual 'interpretation' of the display was even more complex as the more experienced operator would have been able to identify many other aircraft configurations we haven't been able to cover here.
Excellent documentary. I read RV Jones "Most secret War" and "Radar, the invention that changed the world". What a great piece of history, thanks for posting.
Thanks for the positive feedback. Yes, that's a very good book too and well worth reading!
Great stuff! The display is much like a "PAN Scope" except upside down, and used for difference in distance, not difference in frequency. Thanks for sharing this!
Glad you liked it. Indeed, there were several other types of similar 'A'' screen displays in use at about the same time, featuring both upwards and downwards pointing pulses, with some even using a combination of both!
This is a very good video. After I watched it I noticed that you made a comment. I love Mr. Carlson's Lab. I've learned a ton from your excellent videos....thanks Mr. Carlson
Time not distance
@@michaelshore2300 Hi Michael, is radar not used to judge distance? Yes it does this through reflection time, much like time domain reflectometry, but the end result is distance, is it not?
@@MrCarlsonsLab radar measures time to work out distance a TDR does exactly the same thing.
Philco made IFF units at 3130 West Monroe Street in Sandusky, Ohio. Today, that's the Okamoto Sandusky Manufacturing, Llc building. If you look closely, you can see the old "Philco" sign over the door in Art Deco Stainless steel. 73 DE W8LV BILL
Interesting. Sounds much like here in the UK, where most electronic products used to be made in this country using UK sourced components. I doubt if anything remains of the industry today :-(
Chain Home used 27MHz and an improved version, Chain Home Low, used 40MHz which allowed greater resolution and so could see low flying targets. The transmitters just illuminated a broad area.
Quite right Billy.
@@lishaton The reason for the choice of 27 MHz is more interesting. While most scientist agreed the higher frequency the better Watson Watt was more practical and de asked "what gave the best reflection ?" A dipole "what was the wing span of a German bomber?" average about 80 feet so that set the frequency and UK industry had equipment available at about that frequency. The goniometer was used on the receive signal and gave Bearing but very poor height information . Radar Technician Locking 1953
@oml81mm Rubbish!!! Chain Home Low was a beam radar with a turntable aerials. It was based on the early ASV/AI radar frequency of 200 MHz and development was originally done as a coastal defence (CD) gun laying radar for the Army. Development started for the Army CD set in 1938 and the redesign to convert them to CHL for the RAF started in July 1939. Switched lobe receive aerials were built into the design from the start so an operator could compare two opposite peaks on the CRT and turn the aerials until they got two equal peaks that gave accurate bearings. Range resolution wasn't so hot and there was no height finding. Maximum range was 25 miles and minimum height was 500 feet over the sea. The first CHL radars were pretty much all lash up experimental equipment's using whatever suitable transmitter and receiver systems were available, so no two stations were alike. First Operational CHL station ready by April 1940, 25 in service by the start of the Battle of Britain, however a number of them were based initially on modified Army Gun-Layer (GL) Mk 1 sets which worked at 54.5 to 85.7 MHz. By the start of 1941 plans were in place to upgrade all of the CHL equipment to a common standard with 60 mile range high power transmitter, Single Antenna with T/R Switch for common Transmit / Receive, Motorised Antenna Rotation (instead of hand crank) and a PPI display. 5 such systems were operational by the end of 1941, the first being operational in August 1941).
40MHz kit was the Mobile RDF Unit (MRU), a truck mounted transportable CH system for overseas use by the Army and Battle Damage cover radar for the CH system.
Thanks for the input Richard.
Excellent video. Unashamedly, I learnt something!
Glad you found it interesting :-)
Bravo! Excellent. From here in the States we thank you for sharing!
You're most welcome. Thank you!
Hey I know your site from years ago already!
Didn't see an Allied collection of radars online yet.
Finally! Good work mate!
Ah well, a few good things came out of lockdown :-) !!
When Wimperis sought an expert in radio to help judge the death-ray concept, he was naturally directed to Watt. He wrote to Watt "on the practicability of proposals of the type colloquially called 'death ray'" The missing technique that made radar practical was the use of pulses to determine range by measuring the time between the transmission of the signal and reception of the reflected signal. This would allow a single station to measure angle and range simultaneously. In 1924, two researchers at the Naval Research Laboratory in the United States, Merle Tuve and Gregory Briet, decided to recreate Appleton's experiment using timed pulsed signals instead of the changing wavelengths.[17] The application of this technique to a detection system was not lost on those working in the field, and such a system was prototyped by W. A. S. Butement and P. E. Pollard of the British Signals Experimental Establishment (SEE) in 1931. The British Army War Office proved uninterested in the concept and the development remained little known outside SEE. wiki
Interesting!
@@lishaton Castles in the Sky is on youtube although it is not pleasant to watch because the top is cut off.
Really cool. High quality content and thanks for posting.
Thanks for the positive comments :-)
Thank you for producing this great video. I have worked as a network engineer monitoring comms systems with alerts that needed to be analysed and responded within minutes of alarms been recorded. The stress levels could be vey high sometimes, when unexpected events occurred. It must have been a boring and tedious job to watch a radar screen for hours and not good for the eyes but their diligence was essential to the safety of x1000s of other people. Do you know of any accounts of radar history written from the perspective of the operators? In my view they don't get enough credit for the work they performed.
Thanks for the positive comments! I agree. It certainly sounded like a very unrewarding but essential job to me. I do not have any account from any of the chain-home operators myself, but am sure there must be. Maybe the Imperial War Museum might have some in their archives??
thanks for another great video, regards Clare
Many thanks once again Clare!
Magnificent, thankyou!
Very pleased that you enjoyed it :-)
And that was only three years after no one could find Amelia Earhart in the south pacific.
2nd. July 1937 - pretty much so!
Thank you. Very interesting.
Thanks for the feedback Glen.
👍Very interesting, thank you.
Thanks for the feedback Steve! :-)
Very interesting, thank you
You're welcome Ben.
I believe all research will be like amnesia, no more radar!!!
I hope you enjoyed the video!
Without the military might of America ... us British would be doing the ‘Goose Step’.
True!
In the context of this development , it had little to do with the military might of the US. Uk was miles ahead of the Yanks.
My guess is who ever wrote that, is a historicaly ignorant yank.
Without British Know-how, we might ALL being doing The Goose step.
Out of all the reasons we are not doing the Goose Step - we owe the greatest debt to Communist Russia. They'd already pretty much defeated the Nazi's before Merica had a real impact. Oh - and the wonderful people at Bletchly Park
Have I got this right?
To find the position of an incoming enemy formation you needed at least two neighbouring transmitter/receiver stations: A and B, say.
Although you were not able to measure the bearing of the formation from station A, you could measure its range. The same was true for B.
Draw an arc, centred on station A, with with a radius equal to the range from A. Draw a similar arc centred on B. The point where the two arcs intersect is the position of the enemy formation.
Essentially yes. As you've just said, using the info. from just one, then whilst you know how far it is from that particular transmitter station, but wouldn't know it's bearing. With later radar devices such as the ASV radar, although just one transmitter is still used, by having a receiving aerial on both wings of the aircraft, it was then possible to home in on it.
The Chain Home receiver has a pair of orthogonal dipoles, supported by four masts, a goniometer is used to find approximate bearing from these inputs . Triangulation from a pair of stations could give a better fix but was not essential.
@@paulpotter1041 Yes, I had noticed that the receiving masts were arranged in the form of a square whereas the four transmission masts were in a straight line. It made me wonder if this was a precursor of the high-frequency direction-finding (HF/DF or "Huff Duff") aerial system used by convoy escort ships to locate the bearing of short transmissions by U-boats in the Atlantic.